Well, as long as the tire can increase slip-angle under increasing load then that is a gain in traction even though it is also increasing drift. See, if the tire takes a larger load without sliding then that is more traction demonstrated. This fundamental relates to either increasing speed and g-force in a curve or to a re-balancing of front-to-rear load transfer.

Now very stiff tires can take very large loads and that's how it's done. But a stiffer suspension is not an increase in load-transfer but just faster load-transfer. And that's why an increase in load-transfer is more traction on the turn-in. The balance of the front-to-rear load-transfer can be changed and the speed of the load-transfer can be changed but not the total load-transfer. Well, I mean that the total peak load-transfer is not changed with suspension stiffness. It can be changed with vehicle height or with vehicle track-width.

To relate all this back to bicycles, it could be said that many bicycles, like go-karts, just use tires and frame or fork deflection for a suspension.